Mechanism for unfolding signatures

ABSTRACT

This invention includes a mechanism for unfolding signatures so that inserts can be put in the central fold. The signature, of which an example is a tabloid, comprises a plurality of folded, substantially identically-sized flat sheets of paper, each folded sheet being inserted within the fold of its next contiguous sheet so that a common center fold for the signature is formed with the successsive sheets formed as embracing layers. Each successive outer layer is underlapped at its free edges relative to the free edges of the layer next innermost to it, by which means a tapered free edge is formed. The means comprises a supporting table, a sucker wheel with an axis of rotation, and a perforated peripheral surface with a peripheral tangential speed equal to the forward speed of the signature so as periodically to engage the uppermost portion of a folded structure. A transfer means moves the folded structure along the supporting table in a path parallel to the center fold at said forward speed. A source of subatmospheric pneumatic (suction) pressure is periodically connected to the perforated peripheral surface by timer means. A shelf overlays at least a part of the supporting table and receives the free edge which is lifted by the sucker wheel. According to a preferred feature of the invention, the sucker wheel is driven by a motor, and the timer means connects the peripheral surface to subatmospheric pressure with a frequency less than the frequency of revolution of the sucker wheel.

United States Patent [72] Inventor Lyle V. Dutro 1660 Carriage House Road, Pasadena, Calif. 91 107 [21] Appl. No. 749,054

July 31, 1968 122 Filed Feb. 9, 1911 [45] Patented [54] MECHANISM FOR UNFOLDING SIGNATURES 9 Claims, 11 Drawing Figs.

Primary Examiner-Lawrence Charles AttorneyAngus and Mon ABSTRACT: This invention includes a mechanism for unfolding signatures so that inserts can be put in the central fold. The signature, of which an example is a tabloid, comprises a plurality of folded, substantially identically-sized flat sheets of paper, each folded sheet being inserted within the fold of its next contiguous sheet so that a common center fold for the signature is formed with the successsive sheets formed as embracing layers. Each successive outer layer is underlapped at its free edges relative to the free edges of the layer next innermost to it, by which means a tapered free edge is formed. The means comprises a supporting table, a sucker wheel with an axis of rotation, and a perforated peripheral surface with a peripheral tangential speed equal to the forward speed of the signature so as periodically to engage the uppermost portion of a folded structure. A transfer means moves the folded structure along the supporting table in a path parallel to the center fold at said forward speed. A source of subatmospheric pneumatic (suction) pressure is periodically connected to the perforated peripheral surface by timer means. A shelf overlays at hast a pa rt of tl s upporting table and receives the free edge which is lifted by the sucker Wheel.

According to a preferred feature of the invention, the

sucker wheel is driven by a motor, and the timer means connects the peripheral surface to subatmosphen'c pressure with a frequency less than the frequency of revolution of the sucker wheel.

MECHANISM FOR UNFOLDING SIGNATURES This invention relates to a mechanism for unfolding a signature such as a tabloid and which can be used with certain fold structures to open them at their precise center fold.

Tabloid structures comprise a plurality of folded, substantially identically-sized sheets of paper. Each folded sheet is inserted within the fold of its next contiguous sheet so that a common center fold for the signature is formed with the successive sheets formed as embracing layers. Each successive outer layer is underlapped at its free edge relative to the free edge of the layer next innermost to it, whereby a tapered free edge is formed. Stuffing of papers is customarily regarded as a second operation in the printing industry, because the press capacity is limited, and it is not feasible to build up the press to the size needed for constant supply, Furthermore, many articles to be inserted are sent in from outside and haveno relationship to press operations. Devices exist for opening these structures, but in general they are so complex, bulky and expensive as to be unsuitable for small to moderately large installations. Accordingly, it is common practice in the newspaper art to pay men to stuff the papers by hand. This greatly increases the cost of the product, and prices out of the market much potential business. It is an object of this invention to provide means and method whereby the signature is reliably opened mechanically and at high speed in a rugged, relatively small and inexpensive device. With a specific folded structure, opening at the precise center fold can be achieved.

A device according to this invention comprises a supporting table, a sucker wheel having an axis of rotation and a perforated peripheral surface adapted to rotate adjacent the tapered free edge of a signature which is supported by the said supporting table. The sucker wheel periodically engages the free edges of an uppermost portion of the folded structure. Transfer means moves the folded structure along the supporting table in a path parallel to the center fold.

A subatmospheric pneumatic pressure source is periodically connected to the perforated peripheral surface by timer means. A shelf overlays at least part of the supporting table for receiving the edge engaged by the sucker wheel. The shelf is parallel to the fold and adjacent to the sucker wheel so that it receives the upper free edge and holds the signature open, allowing for insertion of a signature within the opened fold.

According to a preferred but optional feature of the invention, the sucker wheel is driven by a motor, and the timer means is so adapted as to connect the subatmospheric pressure to the peripheral surface at afrequency which is less than the frequency of revolution of the sucker wheel, whereby a sucker wheel of markedly reduced radius can be used.

The above and other features of this invention will be fully understood from the following detailed description and the accompanying drawings, in which:

FIG. 1 is an illustration of a group of sheets intended to be formed into a signature;

FIG. 2 shows the presently preferred folded signature structure of the invention;

FIG. 3 is a top view taken at line 3-3 of FIG. 2;

FIG. 4 is a side cross section of the presently preferred embodiment of the invention;

FIG. 5 is a side oblique elevation, partly in cutaway cross section, taken at line 5-5 of FIG. 4;

FIG. 6 is a fragmentary view of FIG. 5 showing another operating condition;

FIG. 7 shows a control system for part of the device FIG. 4;

FIGS. 8 and 9 are cross sections taken at lines 8-8 and 9-9 of FIG. 7;

FIG. 10 shows a portion of FIG. 7; and

FIG. 11 shows a second signature being inserted into the first one at an open fold. A stack 10 of sheets I1 is shown in FIG. 1, with the sheets lying flat, one atop the other to form a rectangular erect stack. Two lines are indicated. The first is a center line 12 which is parallel to the left and right-hand edges and equidistant between them. The second is a fold line 13 which is also parallel to the same edges, but is closer to one than to the other.

A signature of the type which is preferred for use with the device is shown in FIG. 2, formed by folding stack I0 around line 13 so as to form a folded structure 14. Because of the different radii of curvature at the center line, the edges will he stepped back from each other, each successive outer layer being underlapped at its free edge relative to the free edge of the layer next innermost to it. By underlapped is meant lying farther away from the extreme edge. Free edge I5 of the folded structure completely overlays underlying edge 16 so as to shield all of edges of underlaycr 16. The fold was, of course formed by moving the left-hand portion of the stack through arc I7. The resulting structure is shown in plan view in FIG. 3. This structure can be opened to its precise center fold.

The objective now is to open structure 14, preferably but not necessarily at its precise center 18 so that another object. such as another signature, can be placed therein.

The machine is shown in FIG. 4, wherein a supporting table 20 is shown, which preferably has a slanting planar surface 21. such that the signature rests on surface 2] and slides along against a curb 22 which extends in the direction of motion, which direction is normal to the plane of FIG. 4. Transfer means 25 includes a peg 26 which is driven by a continuous chain 27. The peg extends a slot 28 in the supporting table and as it moves along the slot shoves the signature along the table in its direction of motion. The slot is parallel to the direction of motion.

A sucker wheel 30 overlays the table and rotates around an axis 31, which is normal to the center fold and which in the preferred embodiment lies at an oblique angle to surface 21. Preferably, the peripheral surface is cylindrical, and axis 31 is parallel to the tapered edge. The degree of taper of the free edge is exaggerated, as is the thickness of the sheets, for purposes of illustration.

The sucker wheel has a plurality of perforations 32, which preferably extend in a relatively narrow, axially oriented band across the peripheral surface. They connect to an internal passage 33 which opens onto a shear-seal face 330 of the wheel. A face plate 34 has a matching shear-seal face 35 with two angular suction and vent ports 36 and 37, respectively, adapted to make periodic and alternate registration with passage 33. The face plate does not rotate. It is fixed to the table structure. The wheel is rotatably mounted to the table structure by a bearing 38 and driven by a motor 39.

The shear-seal arrangement comprises timer means to periodically connect passage 33 with a source of subatmospheric pneumatic pressure. Vent port 37 is optional, because leakage through the perforations can act as a vent. However, when used it acts as a quicker vent and a means for alternate connection of passage 33 to suction and exhaust.

The timer arrangement thus far disclosed is adequate when the diameter of the wheel is large enough that its perimeter is about equal to the length of the fold, because then there is a valving action timed by the shear-seal plates for each revolu tion. However, this requires an inconveniently large wheel which adversely interferes with adjacent mechanisms.

Accordingly, the preferred timer means further includes means for connecting passage 33 to suction with a frequency less than that of the frequency of revolution of the wheel. Then a relatively small wheel can be used.

The timer means so adapted includes a three-way valve 41 connected by conduit 41a to port 36 with two alternate conditions. The first connects the conduit to the source of subatmospheric pressure, in this case, vacuum pump 41b, and the other connects it to a vent 42 to atmosphere. This can provide an alternating pressure within the sucker wheel when port 36 is registered with passage 33. As will be seen, this will occur with a lesser frequency.

The sucker wheel is driven by motor 39 which also drives a speed reducer 44, the speed reducer driving a cam 45 (FIG. 8), which cam operates the three-way valve by means of a stem 46 connected to the three-way valve itself. Therefore the frequency of rotation of the wheel is governed by the motor, but the frequency of the pulsating pressure is determined by the speed or the shape of the cam, or of both, whereby the wheel may make two or more revolutions with the pressure applied only during a portion of one of the revolutions. This enables the wheel to rotate adjacent to the free edge of the folded signature with the suction applied only at a specific time to be described below and without exerting suction during a major part of its rolling movement. A markedly smaller wheel can be used, rather than one whose perimeter is greater than the length of the free edge. A smaller device can be made, and more freedom of design and timing is provided. The timer means of H65. 5l0 is, of course, only a single example of a means periodically to contact the periphery of the wheel to the source.

As can best be seen in FIG. 4, axis 31 is inclined so as to be generally parallel to the stepwise angle of the free edge, and the wheel is adjacent to it so that suction exerted by the wheel will draw the upper most one of the free edges against its periphery. Actually, a substantial spacing is possible, on the order of one-fourth inch or so, because the air flow to the sucker wheel will usually draw the edge to it. In FIG. 5, a signature 14 is shown just arriving at the sucker wheel. At this time, the valve will be set such that suction will be applied to port 36, port 36 will register with passage 33, and the leading edge 50 of the signature will thereupon be engaged and held by the sucker wheel and bent by it upward as it rotates as sh wn in FIG. 6.

immediately adjacent to the sucker wheel a stationary shelf 51 is provided where it will underly this free'edge as soon as it is lifted by the sucker wheel. Shortly after the position of FR]. 6,.the timer means either vents the sucker wheel or simply disconnects it from suction, and the wheel will release the edge. The upper free edge then travels along the shelf, the shelf serving to hold the signature open.

A nozzle 52 may be provided to force a blast of air from a pump 53 into the fold so as to facilitate the separation, especially after the sucker wheel releases the edge. It is located directly underneath the shelf and may if desired emit from nozzles formed in the shelf itself.

FIG. 11 shows the upper fold of the signature resting on the shelf, and the lower fold resting on the supporting table. Another signature 55 is being shown thrust into the open structure. Shortly after this position, the shelf ends, permitting the top fold to fall onto the insert, and the transfer means pushes the assembled structure to receiving means, where it is disposed of.

This invention provides a simple and reliable means for opening a folded structure. Should absolute reliability of location of the center fold at the very center be desired, the folded structure will overlap in the manner shown in H6. 2. The device has considerable utility in both techniques. However, the use of a fold which is offcenter provides the additional advantage of making certain that the fold will be opened at the precise center, and this is a feature which has long been sought in the art without having been met in inexpensive, rugged and reliable equipment.

This invention is not to be limited by the embodiment shown in the drawings and described in the description, which is given by way of example and not of limitation, but only in accordance with the scope of the appended claims.

lclaim:

1. Mechanism for opening a signature at its center fold comprising a plurality of folded substantially identically-sized flat sheets of paper, each folded sheet being inserted within the fold of its next contiguous sheet so that a common center fold for the signature is formed with the successive sheets formed as embracing layers, each successive outer layer being underlapped at its free edges relative to the free edges of the layer nextinnermost to it, whereby a tapered free edge is formed, said means comprising: a supporting table; a sucker wheel; having an axis of rotationand a perforated peripheral surface adapted to rotate adjacent to the tapered free edge of a signature supported by the said table and of axial length sufficient to overlap the entire lateral extent of the tapered free ed e; means to rotate said sucker wheel; transfcr'means moving 51c folded structure along the supporting table in a path parallel to the center fold; a source of subatmospheric pneumatic pres sure; timer means periodically connecting the said perforated peripheral surface to said source; and a shelf overlaying at least part of the supporting table for receiving the edge contacted by the sucker wheel, said shelf being parallel to said fold and adjacent to the sucker wheel, whereby subatmosphcric pressure applied to the sucker wheel when the advancing comer of the folded structure is adjacent to the sucker wheel causes the leading portion of the tapered free edge to adhere to the peripheral surface, rotation of the sucker wheel in that condition lifting the leading portion onto the shelf, after which the subatmospheric pressure is released and the folded structure then continues to be moved by the transfer means with the lower fold on the supporting table and the upper fold on the shelf.

2. Mechanism according to claim 1 in which the axis of the sucker wheel lies in a plane which is normal to the center fold.

3. Mechanism according to claim 1 in which the axis of the sucker wheel lies in a plane which is normal to the center fold, and at an oblique angle to the plane of the table.

4. Mechanism according to claim I in which the timer means is so disposed and arrangedas to connect the sucker wheel to the source with a frequency less than that of the revolution of the sucker wheel.

5. Mechanism according to claim 1 in which the timer means comprises a port in the sucker wheel and a port in adjacent fixed structure adapted to make periodic registration with one another as a function of rotational position, the port in the fixed structure being connected to the source of subatmospheric pneumatic pressure.

6. Mechanism according to claim 1 in which the' timer means comprises a drive motor drivingly connected to the sucker wheel, a speed reducer driven by the motor, a cam driven by the speed reducer, and a three-way valve actuated by said cam, the three-way valve connecting the peripheral surface alternately to the subatmospheric pressure source with a frequency less than the frequency of revolution of the sucker wheel.

7. Mechanism according to claim 6 in which the axis of the sucker wheel lies in a plane normal to the center fold.

8. Mechanism according to claim 5 in which the timer means additionally includes a cam, a three-way valve actuated by the cam, the three-way valve connecting the port in the sucker wheel alternately to the subatmospheric pressure source with a frequency less than the frequency of revolution of the sucker wheel, the cam being so proportioned and driven at such a speed as to accomplish this result.

9. The method of opening a signature at its center fold which signature comprises a plurality of foldedsubstantially identically sized flat sheets of paper, each folded sheet being inserted within the fold of its next contiguous sheet so that a common center fold is formed with the successive sheets formed as embracing layers, each successive outer layer being underlapped at its free edges relative to the free edges of the layer next innermost to it, whereby a tapered free edge is formed, said method comprising: utilizing a rotating sucker wheel having an axis of rotation oblique to the center fold and an axial length sufficient to overlap the entire tapered free edge, moving the signature in the direction of its center fold and, rolling the sucker wheel along the tapered free edge, engaging the tapered free edge to the sucker wheel along a region of contact at least as wide as the lateral extent of the tapered free edge to lift the leading portion of the tapered free edge onto a shelf, thereby opening the signature precisely at its center fold, releasing the'tapered free edge from the sucker wheel, and moving the signature along, held open by the shelf.

E my UNITED STATES PATENT OFFICE i CERTIFICATE OF CORRECTION i Patent No. 3,561,751 Dated February 9, 1971 Inventor(s) Lyle V. Dutro It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Patent Column 1, line 3 Change "fold" to --folded-- Column 1, line 6 Insert -flat-- before "sheets" Column 1, line 69 "A stack" should begin a new paragraph Column 2, line 23 Insert --thro ughafter "extends" Claim 1, line 9 Delete after "wheel" Signed and sealed this 16th day of May 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

1. Mechanism for opening a signature at its center fold comprising a plurality of folded substantially identically-sized flat sheets of paper, each folded sheet being inserted within the fold of its next contiguous sheet so that a common center fold for the signature is formed with the successive sheets formed as embracing layers, each successive outer layer being underlapped at its free edges relative to the free edges of the layer next innermost to it, whereby a tapered free edge is formed, said means comprising: a supporting table; a sucker wheel; having an axis of rotation and a perforated peripheral surface adapted to rotate adjacent to the tapered free edge of a signature supported by the said table and of axial length sufficient to overlap the entire lateral extent of the tapered free edge; means to rotate said sucker wheel; transfer means moving the folded structure along the supporting table in a path parallel to the center fold; a source of subatmospheric pneumatic pressure; timer means periodically connecting the said perforated peripheral surface to said source; and a shelf overlaying at least part of the supporting table for receiving the edge contacted by the sucker wheel, said shelf being parallel to said fold and adjacent to the sucker wheel, whereby subatmospheric pressure applied to the sucker wheel when the advancing corner of the folded structure is adjacent to the sucker wheel causes the leading portion of the tapered free edge to adhere to the peripheral surface, rotation of the sucker wheel in that condition lifting the leading portion onto the shelf, after which the subatmospheric pressure is released and the folded structure then continues to be moved by the transfer means with the lower fold on the supporting table and the upper fold on the shelf.
 2. Mechanism according to claim 1 in which the axis of the sucker wheel lies in a plane which is normal to the center fold.
 3. Mechanism according to claim 1 in which the axis of the sucker wheel lies in a plane which is normal to the center fold, and at an oblique angle to the plane of the table.
 4. Mechanism aCcording to claim 1 in which the timer means is so disposed and arranged as to connect the sucker wheel to the source with a frequency less than that of the revolution of the sucker wheel.
 5. Mechanism according to claim 1 in which the timer means comprises a port in the sucker wheel and a port in adjacent fixed structure adapted to make periodic registration with one another as a function of rotational position, the port in the fixed structure being connected to the source of subatmospheric pneumatic pressure.
 6. Mechanism according to claim 1 in which the timer means comprises a drive motor drivingly connected to the sucker wheel, a speed reducer driven by the motor, a cam driven by the speed reducer, and a three-way valve actuated by said cam, the three-way valve connecting the peripheral surface alternately to the subatmospheric pressure source with a frequency less than the frequency of revolution of the sucker wheel.
 7. Mechanism according to claim 6 in which the axis of the sucker wheel lies in a plane normal to the center fold.
 8. Mechanism according to claim 5 in which the timer means additionally includes a cam, a three-way valve actuated by the cam, the three-way valve connecting the port in the sucker wheel alternately to the subatmospheric pressure source with a frequency less than the frequency of revolution of the sucker wheel, the cam being so proportioned and driven at such a speed as to accomplish this result.
 9. The method of opening a signature at its center fold which signature comprises a plurality of folded substantially identically sized flat sheets of paper, each folded sheet being inserted within the fold of its next contiguous sheet so that a common center fold is formed with the successive sheets formed as embracing layers, each successive outer layer being underlapped at its free edges relative to the free edges of the layer next innermost to it, whereby a tapered free edge is formed, said method comprising: utilizing a rotating sucker wheel having an axis of rotation oblique to the center fold and an axial length sufficient to overlap the entire tapered free edge, moving the signature in the direction of its center fold and, rolling the sucker wheel along the tapered free edge, engaging the tapered free edge to the sucker wheel along a region of contact at least as wide as the lateral extent of the tapered free edge to lift the leading portion of the tapered free edge onto a shelf, thereby opening the signature precisely at its center fold, releasing the tapered free edge from the sucker wheel, and moving the signature along, held open by the shelf. 